Chandrayan-2 Mission

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Kakarat
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Re: Chandrayan-2 Mission

Postby Kakarat » 07 Sep 2019 20:42

I think ISRO should do a Vikram-R or 2 with a rover as a stand alone mission than expediting Chandrayan-3 Mission. since we already have orbiter around the moon and which is expected to be there for 7 years. We should modify Vikram and the rover based on the data received and may be add a Radioisotope heater units (RHU) or if possible get a RTG from US/NASA to make it functional during Lunar nights

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Re: Chandrayan-2 Mission

Postby Bart S » 07 Sep 2019 20:43

Amber G. wrote:
Karthik S wrote:BTW have you guys seen the way a so called journo was shouting at one of ISRO's scientists ?


This is the same Pallava Bagla of NDTV who not too long ago asked ISRO's SK Sivan in the interview something about how many people will be landing at the moon's Vikram ..(or some thing like that) not making it up -- just see NDTV's interview with Sivan before CY2 was launched) . Sivan calmly explained, that Vikram/CY2 was a unmanned craft!!!
(BTW he tweeted a meaning-less apology but IMO that guy is not fit to work as a journalist)


Look at who crawled out of the woodwork to defend him and NDTV

Some folks are sharing this to show up NDTV as unpatriotic. That’s absurd. While a national outpouring of affection for ISRO is understandable—and in some ways even commendable—in no free country would a journalist be chided for expecting to hear from the head of an organization. https://t.co/lMH5OAJ09A
Sadanand Dhume (@dhume) September 7, 2019


About 10-15 years ago this guy seemed to be one of the few pro-India voices out of the US, but in the recent past has been shown up as yet another C-system/Lutyens cabal (as opposed to India) supporter, not too different from the likes of Mihir Sharma.
Last edited by Bart S on 07 Sep 2019 20:45, edited 1 time in total.

Varoon Shekhar
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Re: Chandrayan-2 Mission

Postby Varoon Shekhar » 07 Sep 2019 20:44

Gagan wrote:Posting a series of twitter posts by the Principal Scientific Advisor GOI:

The precise launch and mission management has ensured a long life of almost 7 years instead of the planned one year. Here is an list of cutting-edge science that will come from the orbiter. From ISRO:


The Vikram Lander followed the planned descent trajectory from its orbit of 35 km to just below 2 km above the surface.

All systems and sensors of the Lander functioned excellently until this point. Tested and proved many new technologies such as the variable thrust propulsion technology used in the Lander.


Whoa, 7 years! Is that a misprint or editing error? SImply fantastic if accurate. Was this part of the hidden message an ISRO spokesman made after the excellent initial orbit of Chandrayaan-2 on earth with an apogee of 45,000km? Remember the spokesman said something like 'we have achieved something major today( with the launch and placement) ' but that they couldn't reveal it at the time. Also was waiting for that info about the new technologies proven on board Vikram. Hope for more details about the many new technologies in the days ahead.

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Re: Chandrayan-2 Mission

Postby UlanBatori » 07 Sep 2019 20:45

Probably a Space Tether is the safest and repeatable way to deliver a rover to the lunar surface.

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Re: Chandrayan-2 Mission

Postby UlanBatori » 07 Sep 2019 20:46

Bart S wrote:
Amber G. wrote:
This is the same Pallava Bagla of NDTV who not too long ago asked ISRO's SK Sivan in the interview something about how many people will be landing at the moon's Vikram ..(or some thing like that) not making it up -- just see NDTV's interview with Sivan before CY2 was launched) . Sivan calmly explained, that Vikram/CY2 was a unmanned craft!!!
(BTW he tweeted a meaning-less apology but IMO that guy is not fit to work as a journalist)


Look at who crawled out of the woodwork to defend him and NDTV

Some folks are sharing this to show up NDTV as unpatriotic. That’s absurd. While a national outpouring of affection for ISRO is understandable—and in some ways even commendable—in no free country would a journalist be chided for expecting to hear from the head of an organization. https://t.co/lMH5OAJ09A
Sadanand Dhume (@dhume) September 7, 2019


About 10-15 years ago this guy seemed to be one of the few pro-India voices out of the US, but in the recent past has been shown up as yet another C-system/Lutyens cabal (as opposed to India) supporter, not too different from the likes of Mihir Sharma.


Cool! Two cretins with one stone.

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Re: Chandrayan-2 Mission

Postby Supratik » 07 Sep 2019 20:46

That is a smartass question. Many science projects don't have immediate value. FYI the experimental fusion reactor ITER is already under construction in France and India is sharing 10% of the cost and building some technologies for it.

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Re: Chandrayan-2 Mission

Postby fanne » 07 Sep 2019 21:00

It has been reported many times that ISRO/DRDO when they test things, they don't go piecemeal, they test to the end. If they are testing just the rocket engine for say a A/A missile, they would also put some active/passive guidance and go all the way to hit the target (and not just test the engine, though testing the engine is the main (but not the only purpose) purpose for that testing.
Similarly, CY-2 will now map moon to the greatest fidelity inn 3D. Next CY-3 does not have to choose the next best spot to land, we will know before hand where it should land and subsequent to that where to de-orbit it from moon based orbit and maybe a direct controlled descent to the known landing spot (Since we have a 30 cm resolution 3 D map).
If you want to look from that perspective, CY-2 real mission was the orbiter to map the moon. The next one would have landed based on the map. But in CY-2 you were going that far and with some extra 5-10% cost give a shot at landing a rover, why not. Ya they did set the expectation, but boy it not a failure, but a success. My 7 year old saw it glued to the TV and now she is defending that how it is success and how the orbiter is 95% of the experiment etc etc. Imagine this level of wisdom for a 7 year old!! The success would have been great, but the failure is bringing the patriots out and also inspiring them to do something, anything (even if it is in their childish imagination). They have taken upon themselves to solve the problem and if you hear them, their solution is so out of box....and very scientific.
Congrats ISRO...it was a success and you are an inspiration!!

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Re: Chandrayan-2 Mission

Postby arvin » 07 Sep 2019 21:09

Kakarat wrote:I think ISRO should do a Vikram-R or 2 with a rover as a stand alone mission than expediting Chandrayan-3 Mission. since we already have orbiter around the moon and which is expected to be there for 7 years. We should modify Vikram and the rover based on the data received and may be add a Radioisotope heater units (RHU) or if possible get a RTG from US/NASA to make it functional during Lunar nights


After RCA of yesterday, vikram 2 should be done.
MOM weighed 1347 kg and was lofted by workhorse PSLV XL.
Vikram + pragyan will come to around 1500 kg and could be doable using the workhorse. Aditya L1 is scheduled for may 2020 using XL. Maybe swap it for vikram 2.

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Re: Chandrayan-2 Mission

Postby Amber G. » 07 Sep 2019 21:10

Sharing - Must read in this audience: (could not have said better myself :) )
From Twitter/ FB From NaMo's principal scientific adviser on Chandrayaan-2.
Principal Scientific Adviser, Govt. of India

After a moment of despondency, it is back to work!! It is inspirational to see this characteristic of science in collective action. Kudos to ISRO - Indian Space Research Organisation" Here's the text from the Twitter thread:

Since the launch of Chandrayaan-2 on July 22, 2019, India and the world watched its progress from one phase to the next with great expectation and excitement.

The Chandrayaan-2 mission is very complex, and a significant technological leap from previous missions of ISRO. This brought together an Orbiter, Lander and Rover to explore the unexplored south polar region of the Moon.

This unique mission, aimed at studying not just one area of the Moon but also its exosphere, the surface and sub-surface in a single mission.

The Orbiter has already been placed in its intended orbit around the Moon and shall enrich our understanding of the moon’s evolution, map minerals, water molecules in the polar regions, using its eight state-of-the-art scientific instruments.

The precise launch and mission management has ensured a long life of almost 7 years instead of the planned one year. Here is an list of cutting-edge science that will come from the orbiter. From ISRO:

The Orbiter camera is the highest resolution camera (0.3m) in any lunar mission so far and has already started providing high-resolution images which will be immensely useful to the global scientific community.

Orbiter camera: The pictures I saw this morning were truly extraordinary. TMC 2 is a miniature version of the Terrain Mapping Camera used onboard the Chandrayaan 1 mission.

TMcv2’s primary objective is mapping the lunar surface in the panchromatic spectral band (0.5-0.8 microns), high spatial resolution(5m), swathe(20 km from 100 km lunar polar orbit). Data will give clues about the Moon's evolution, prepare 3D maps of the lunar surface.

CLASS measures X-ray Fluorescence (XRF) spectra to detect elements such as Magnesium, Aluminium, Silicon, Calcium, Titanium, Iron, and Sodium. The XRF technique will detect these elements by measuring the characteristic X-rays they emit when excited by the Sun's rays.CLASS measures X-ray Fluorescence (XRF) spectra to detect elements such as Magnesium, Aluminium, Silicon, Calcium, Titanium, Iron, and Sodium. The XRF technique will detect these elements by measuring the characteristic X-rays they emit when excited by the Sun's rays.

XSM observes the X-rays emitted by the Sun and its corona, measures the intensity of solar radiation in these rays, and supports CLASS. Provides solar X-ray spectrum in the energy range of 1-15 keV

XSM will provide high-energy resolution and high-cadence measurements (full spectrum every second) of solar X-ray spectra as input for analysis of data from CLASS.

Imaging Infra-red spectrometer (IIRS) has two primary objectives: i. global mineralogical and volatile mapping of the Moon in the spectral range of ~0.8-5.0 µm for the first time, at the high resolution of ~20 nm.

IIRS second objective: Complete characterization of water/hydroxyl feature near 3.0 µm for the first time at high spatial (~80 m) and spectral (~20 nm) resolutions.

One more from IIRS: will also measure solar radiation reflected off the Moon's surface in 256 contiguous spectral bands from 100 km lunar orbit.

Dual-frequency (L and S) synthetic aperture radar (SAR) will provide enhanced capabilities compared to Chandrayaan 1's S-band miniSAR in areas such as: L-band for greater depth of penetration (About 5m — twice that of S-band).

SAR: Circular and full polarimetry — with a range of resolution options (2-75 m) and incident angles (9°-35°) — for understanding scattering properties of permanently shadowed regions.

SAR: The main scientific objectives of this payload are: High-resolution lunar mapping in the polar regions. Quantitative estimation of water-ice in the polar regions. Estimation of regolith thickness and its distribution.

Chandrayyan Atmospheric compositional explorer 2 (CHACE 2) will continue the CHACE experiment carried out by Chandrayaan 1.

CHACE 2 is a Quadrupole Mass Spectrometer (QMA) capable of scanning the lunar neutral exosphere in the mass range of 1 to 300 amu with the mass resolution of ~0.5 amu.

CHACE 2's primary objective is to carry out an in-situ study of the composition and distribution of the lunar neutral exosphere and its variability.

Dual Frequency Radio Science Experiment (DFRS) To study the temporal evolution of electron density in the Lunar ionosphere.

DFRS: Two coherent signals at X (8496 MHz), and S (2240 MHz) band are transmitted simultaneously from satellite, and received at ground-based deep station network receivers.

The Vikram Lander followed the planned descent trajectory from its orbit of 35 km to just below 2 km above the surface.

All systems and sensors of the Lander functioned excellently until this point. Tested and proved many new technologies such as the variable thrust propulsion technology used in the Lander.

Success criteria were defined for each and every phase of the mission and so far 90 to 95% of the mission objectives have been accomplished and will continue to contribute to Lunar science. notwithstanding the loss of communication with the Lander.

@isro project review teams made presentations to mission management, Chaired by Dr. Sivan right through the early hours of today onward. They are already addressing causes and learning from the events.

After a moment of despondency, it is back to work!! It is inspirational to see this characteristic of science in collective action. Kudos to @isro

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Re: Chandrayan-2 Mission

Postby Gagan » 07 Sep 2019 21:27

arvin wrote:
Kakarat wrote:I think ISRO should do a Vikram-R or 2 with a rover as a stand alone mission than expediting Chandrayan-3 Mission. since we already have orbiter around the moon and which is expected to be there for 7 years. We should modify Vikram and the rover based on the data received and may be add a Radioisotope heater units (RHU) or if possible get a RTG from US/NASA to make it functional during Lunar nights


After RCA of yesterday, vikram 2 should be done.
MOM weighed 1347 kg and was lofted by workhorse PSLV XL.
Vikram + pragyan will come to around 1500 kg and could be doable using the workhorse. Aditya L1 is scheduled for may 2020 using XL. Maybe swap it for vikram 2.

Even a Mk-2 GSLV could do that.
But Vikram and Pragyan were quite limited in what they could do,
Time for bigger and better things by ISRO - really go for a pathbreaking lander/rover.
ISRO is quite near the very cutting edge of human space achievements, in the sense that satellites and landers on Solar System planets are being done by several space powers. Time to do Satellites and Rovers for Venus, Mars, Asteroids etc. Just GO FOR IT ISRO !!!!

Use everything possible, it is time to make humanity proud

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Re: Chandrayan-2 Mission

Postby Amber G. » 07 Sep 2019 21:36

Varoon Shekhar wrote:
Gagan wrote:

Whoa, 7 years! Is that a misprint or editing error? SImply fantastic if accurate. Was this part of the hidden message an ISRO spokesman made after the excellent initial orbit of Chandrayaan-2 on earth with an apogee of 45,000km? Remember the spokesman said something like 'we have achieved something major today( with the launch and placement) ' but that they couldn't reveal it at the time. Also was waiting for that info about the new technologies proven on board Vikram. Hope for more details about the many new technologies in the days ahead.

Actual life, most likely, will be/could be *more* than that. ..and it is no secret. The present orbit could be maintained for decades (or even longer).. interest may die earlier, but the orbit (and enough power to communicate with outside) can remain for a very long time indeed.

CY-1 is still there - at least the craft is still going in orbit with a fairly stable orbit.

Problem with CY-1 at 100 km orbit was heat - inside temperature was reaching very high for electronics to work, so they raised the parking orbit later to 200 km. We learned how our calculations were sort of inaccurate as infrared radiation from moon (which was heating up things inside CY)

CY-2 has better insulation/cooling mechanism for its electronics so 100 km orbit could be maintained for quite some time.

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Re: Chandrayan-2 Mission

Postby EswarPrakash » 07 Sep 2019 21:36

When Rama asked for the moon

I could not stop myself from writing what I felt

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Re: Chandrayan-2 Mission

Postby ramana » 07 Sep 2019 21:38

From WA

Former ISRO scientist - Jijith Nadumuri Ravi

Very emotional moments yesterday night. For a space scientist, the pain of loss of a launch vehicle or a satellite or a spacecraft after ten years of hardwork, is a highly emotional affair. The agony is no less than the pain of a mother on the loss of a new born baby soon after delivery, after long wait and expectation of ten long months!

The graphs were going perfect till the last moment. But soon after the high precision soft landing menuver, close to 1.9 km, a deviation of actual trajectory versus expected trajectory was noticed, but it was within the allowed range variability. But when the vikram lander was close to 300 meters to touch down, we lost signal.

This could be due to some glitch in the communication systyem in the lander (as i hinted in my previous post as one of the horrible errors that could mar the landing missions) or due to the disintegration of the whole lander itself, due to some issue in the soft landing thrusters. Excessive thrust can destabilze the lander. Loss of all fuel can led the lander into a free fall and crash on the surface. It is not clear if the lander came into contact with some 300 meter mountain peak, on its way.

If it was only a communication loss, the lander could evan have already landed safely unable to tell us that it did. But still for the Pragyan rover to come out, we require manual command to be sent which is not possible as we have lost signal contact with the lander and the rover. In this case, the Pragyan rover will for ever remain caged in an intact Vikram lander, both unable to communicate to their makers on Earth.

ISRO is investigating the causes and we would know things clearly soon.

What transpired later on Earth shows the innocence of a space scientist as his baby is lost in space. You can see the PM consoling a weeping ISRO Chairman by giving the comfort of his shoulders. Really touching and emotional moment. It brought tears into my eyes.

Out of three GSLV launches in which i was involved, one was a failure and the hurt felt is still fresh in my mind.

All is not lost.

The Chandrayan 2 orbiter is intact and healthy and will do science for the whole one year. If the landing spot is within the visibility range of the orbiter, its eyes can even detect the remains of the lander, its baby lost in the vastness of the lunar surface. The whole lander is around 2 meters in size. If it is intact it will be easier to spot by the Chandrayan 2 orbiter and if it has disintegrated into pieces, it will be much difficult to spot the small pieces in the lunar surface scans by the orbiter

We can also initiate a follows up replication mission (Chandrayan 3) after studying the faults and incorporating corrections.

In science, every failure is a great teacher.

The lessons are priceless !

And we move on.

---------------------------------------
Note:-
----------------------------------------
Some initial analysis report from ISRO indicates that one out of the four thrusters (retro rockets that act as speed breakers) underperformed. This resulted in the other three thrusters to compensate by over performing. This tug of war between thrusters will cause spacecraft to spin uncontrollably and eventually crash land.

Next time around we will plan manual override for the retro rocket thrusters for the lander to mitigate such thruster issues in automatic mode.

Light speed delay is 1.3 seconds from. Earth to Moon. So total signal delay for manual override will be 2.6 seconds, which is still good for manual control for mission activities lasting for few minutes, like this 20 minute long landing process.

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Re: Chandrayan-2 Mission

Postby Varoon Shekhar » 07 Sep 2019 21:56

arvin wrote:
Kakarat wrote:
After RCA of yesterday, vikram 2 should be done.
MOM weighed 1347 kg and was lofted by workhorse PSLV XL.
Vikram + pragyan will come to around 1500 kg and could be doable using the workhorse. Aditya L1 is scheduled for may 2020 using XL. Maybe swap it for vikram 2.


That's a super idea. Who says that there must be a formal orbiter? Something tells me this is what will happen, though after careful consideration and planning.

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Re: Chandrayan-2 Mission

Postby Varoon Shekhar » 07 Sep 2019 21:59

Amber G. wrote:
Varoon Shekhar wrote:

Actual life, most likely, will be/could be *more* than that. ..and it is no secret. The present orbit could be maintained for decades (or even longer).. interest may die earlier, but the orbit (and enough power to communicate with outside) can remain for a very long time indeed.
CY-2 has better insulation/cooling mechanism for its electronics so 100 km orbit could be maintained for quite some time.


That's great, but of course, for scientists and the lay public alike, it's the smooth functioning of the payloads, all 8 of them, that is being anticipated. If they can beam info/data for 7 years, from an original projection of just one year, that is amazing.

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Re: Chandrayan-2 Mission

Postby Kakarat » 07 Sep 2019 22:07

Gagan wrote:
arvin wrote:
After RCA of yesterday, vikram 2 should be done.
MOM weighed 1347 kg and was lofted by workhorse PSLV XL.
Vikram + pragyan will come to around 1500 kg and could be doable using the workhorse. Aditya L1 is scheduled for may 2020 using XL. Maybe swap it for vikram 2.

Even a Mk-2 GSLV could do that.
But Vikram and Pragyan were quite limited in what they could do,
Time for bigger and better things by ISRO - really go for a pathbreaking lander/rover.
ISRO is quite near the very cutting edge of human space achievements, in the sense that satellites and landers on Solar System planets are being done by several space powers. Time to do Satellites and Rovers for Venus, Mars, Asteroids etc. Just GO FOR IT ISRO !!!!

Use everything possible, it is time to make humanity proud


Image

If Launched by a MkII Vikram 2 can have more instruments, an RHU of 1W heat is 40 gm and a RTG of 300W would be around 60kg and both lander & Rover could be made night proof. current wet weight of vikram is ~1500kg and a MkII can launch >2400kg

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Re: Chandrayan-2 Mission

Postby sudarshan » 07 Sep 2019 22:16

SriKumar wrote:5. Sudarshan: If you look at the embedded video, the craft dropped rapidly at around 3:00 but look at the altitude drop from 3:06 to 3:13. The 7-second update of altitude showed that it had recoved its poise. The altitude drop is around 150 m to 200m (eyeballed it).So its velocity just before loss of signal is around 175/7 = 25 m/s. So, it clearly recovered and decelerated from the high velocity 150 m/sec number you had calculated in a previous post. No idea what happened after that.

If you look at the expected trajectory i.e. the red line, Vikram has reached the altitude where it had to start its HOVER, and come vertically down. Perhaps it could not swtich to the hover mode (speculation) but it was also several 100 meters short of the expected landing spot- which may still be OK as long as the ground is flat. Maybe a combination of events, but am pretty sure ISRO has the data from where things started to depart from expected lines.


Yep, we can hope for the best. Maybe it decelerated enough, and maybe the problem is just that the communication is gone. If it is the latter, then the rover is useless anyway (unless some future mission somehow recovers it and gets to analyze its stored data). But it would have proved a point about being able to soft land. I suspect in that case, it will become like Pokhran-2, where questions were repeatedly raised about the "actual yield." "India claims it soft-landed, but doubts and questions remain..." yada yada. We'll see what the orbiter can tell us - maybe the rover is out and about having a fun time as we speak :).

So the orbiter is in polar orbit, which means, as the moon rotates, the orbiter will get to see (theoretically) every square meter of the moon's surface? This is awesome! A full 3-d map of the moon. This is not the same as real-time GPS, (or LPS - Lunar Positioning System - in this case) but the 3-d map is a gold-mine. Seven years should be long enough to generate some stunning data.

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Re: Chandrayan-2 Mission

Postby vasu raya » 07 Sep 2019 22:17

if needed, with all that fuel maybe they can take the Orbiter to a 35km elliptical orbit and take detailed images of the lander and its location. if it sounds risky, maybe it can be done on a future lunar day once the Orbiter's primary mission is done unless one is in a hurry for the lander replacement mission.

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Re: Chandrayan-2 Mission

Postby Rishi_Tri » 07 Sep 2019 22:25

ramana wrote:From WA


The graphs were going perfect till the last moment. But soon after the high precision soft landing menuver, close to 1.9 km, a deviation of actual trajectory versus expected trajectory was noticed, but it was within the allowed range variability. But when the vikram lander was close to 300 meters to touch down, we lost signal.

Some initial analysis report from ISRO indicates that one out of the four thrusters (retro rockets that act as speed breakers) underperformed. This resulted in the other three thrusters to compensate by over performing. This tug of war between thrusters will cause spacecraft to spin uncontrollably and eventually crash land.

Next time around we will plan manual override for the retro rocket thrusters for the lander to mitigate such thruster issues in automatic mode.

Light speed delay is 1.3 seconds from. Earth to Moon. So total signal delay for manual override will be 2.6 seconds, which is still good for manual control for mission activities lasting for few minutes, like this 20 minute long landing process.


Hypothetical question - given that the lander was so close, would it have landed had it been manned mission? with 'antrikh yatri' guiding the final descent?.. Oh man, came so close!!

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Re: Chandrayan-2 Mission

Postby Gagan » 07 Sep 2019 22:29

Orbiter main Camera has a 30 cm resolution.
Vikram has a 2 m diameter. They should be able to spot it.

If Vikram ran into a small hillock, then it could damage and roll down the slope of the hillock, damaging its antenna

But one thruster failed / performed suboptimally, and software caused the others to throttle up further destabilizing the level.

Sounds like the recent Tesla Crash where advanced cruise control was engaged.
These AIs are notorious I tell you!

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Re: Chandrayan-2 Mission

Postby Gagan » 07 Sep 2019 22:30

By now they probably have pictures of the impact point with the dust cloud there.
Wonder if this was CFIT situation, where Vikram ran into a hillock !

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Re: Chandrayan-2 Mission

Postby SriKumar » 07 Sep 2019 22:50

sudarshan wrote:
SriKumar wrote: Yep, we can hope for the best. Maybe it decelerated enough, and maybe the problem is just that the communication is gone. If it is the latter, then the rover is useless anyway (unless some future mission somehow recovers it and gets to analyze its stored data). But it would have proved a point about being able to soft land. I suspect in that case, it will become like Pokhran-2, where questions were repeatedly raised about the "actual yield." "India claims it soft-landed, but doubts and questions remain..." yada yada. We'll see what the orbiter can tell us - maybe the rover is out and about having a fun time as we speak :).
That would be something if the craft landed and the rover is gallivanting around moonscape having a jolly time. I was thinking about the control system for auto-correction of trajectory and why it went awry. It is a good sign that it slowed down the craft 500 m above surface, so it was working. If we get pictures of the crashed lander, I think it would be possible to estimate the final vertical velocity of the lander (and its orientation) a microsecond before the crash by the degree of damage to the lander and depth of penetration into lunar surface (with impact simulations) assuming we know the elasticity of lunar rock, pebbles, dust (which we have some idea of, with the moon impact probe done with CY1).

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Re: Chandrayan-2 Mission

Postby SriKumar » 07 Sep 2019 22:54

Gagan wrote:Orbiter main Camera has a 30 cm resolution.
Vikram has a 2 m diameter. They should be able to spot it.

If Vikram ran into a small hillock, then it could damage and roll down the slope of the hillock, damaging its antenna

But one thruster failed / performed suboptimally, and software caused the others to throttle up further destabilizing the level.

Sounds like the recent Tesla Crash where advanced cruise control was engaged.
These AIs are notorious I tell you!
Yes, the orbiter should be able to spot it. And maybe that was the function of the orbiter, to keep an eye on the lander. About hillock, I am assuming that ISRO would have known about any large features (5 meters or more) and kept the lander clear of it (but definiely the lander was several 100 meters away from the landing site, horizontally). The (AI) software steering the craft would have had many new components. Very tricky.

Rishi_Tri:
If ISRO cannot autnomously land a craft, there's no way they'll send a human to do it. ISRO has to understand *everything* about landing a craft safely on moon -before- a human is put in it.

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Re: Chandrayan-2 Mission

Postby Haridas » 07 Sep 2019 23:00

UlanBatori wrote:
The whole purpose of Vikram and Pragyan was to determine water if there was water in the lunar soil and H3. This science discovery was a loss not just for India, but the whole of humanity.

I will respectfully diss the veteran Expert who said that yesterday during the run-up on Republic TV. Probably jinxed the lander so much that even Dilbullah's spell could not shake that jinx.

Desis in general and ISRO in particular should emphatically :roll: :P at both these notions. Just think a bit:

There may be a tiny bit of "water" in the lunar pole craters. IF it is there (we will get to that..) it is because some comets etc crashed deep enough into the moon that not all the water was vaporized/dissociated and expelled into Space. Near the south polar region there are craters with high enough walls that sunlight never reaches into the crater bottom, so those **VERY FEW**** places MAY still have some "water", present as ice particles at some 50K or whatever the lunar sub-soil temperature is. If it is present, it is a ***PRECIOUS*** resource, that has probably been there for Billions and Billions of years, from a time when comets would regularly crash into the Moon or Earth's atmosphere.

True, this is scientifically important. But most emphatically, it is **NOT** a place to excavate and plunder mindlessly, nor is it a place to steal this irreplaceable resource for (would u believe it!!) "making rocket fuel for trips to Mars and Beyond".

This water ice, like all things beyond Earth, is the "Common Heritage of All Humankind". NOT for plundering. For people in a nation that is PC-ness Incarnate, decrying Colonial Exploitation and Destruction of Native Ecology, screaming about Climate Change and Sustainability, allowing cattle, monkeys, pigs and dogs proliferate on the streets in the name of Respect 4 Nature, to argue to plunder this irreplaceable resource mindlessly, is just mind-boggling in its complete pakiness.

OK, now why do I say that there MAY be water? Wasn't it conclusively demonstrated by Chandrayaan-1 crashing into the south Pole? I think that is excusable once, but it is like "detecting" the temple under the Babri Masjid ruins, by exploding POKHRAN-3 there.

Oh yes! THERE goes a trace of bronze vapor in the mushroom cloud! Had to be from *******'s breastplate, just like seen in the "MB" serial.


COULD it have been because someone tossed a half-bottle of Dasani under the solar panel of CY-1 and forgot, like desis do at wedding parties? OK, Just Kidding....

CY-2 was supposed to be much more gentle, just landing one lander slowly, kicking up some gravel and stones, then sending out a 1cm/sec Rover to collect and examine samples.

Second: the He-3. This is far more bogus than the Polar Water. What exactly is the "promise"? That ONE DAY, it will become possible to run controlled fusion reactors using Helium-3. On a power reactor scale. This would create a market demand for Helium-3, which is a rare isotope, very expensive to generate on Earth. SOOOO expensive that it may pay to mine and extract and bottle it and ship it from the Moon!!!!

At that cost, is it worth having fusion power? Has anyone shown the calculation?
How exactly does one extract lunar He-3? By open-pit mining, scraping the lunar surface down to say 10 meter depth over hundreds or thousands of square kilometers, completely destroying all surface features that might yield scientific data. Then processing the whole "regolith" through machines to extract all the minerals and the volatiles. Then dumping the remails, somewhere, maybe in a crater.

In short, COMPLETELY trashing the lunar surface, all history. And ISRO, dedicated to scientific progress, is arguing that **THIS** was the point of the Vikram and its rover? Then perhaps the Moon reached up and slapped Vikram down?

It is sad to see scientifically and technically educated people parroting such mindless garbage on TV or the Internet.


I am late to the party, I love the ISRO folks. Level headed & passionate at what they do. Mantra of aim very-high even when on low string budget & resouces. Hats off to Dr Sivan and his team.


Yak herder spoke my mind, on sootiyapa of exploiting He3 (or some other Au/Pt) from heavenly bodies for use on earth, that is already turned into crap by greed of few.

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Re: Chandrayan-2 Mission

Postby Ashokk » 07 Sep 2019 23:06

It's possible to find Vikram Lander from Chandrayaan-2 Orbiter: Sivan
A senior scientist told TOI "There is a possibility of finding Vikram lander with the orbiter within three days. This is because an orbiter takes three days to come to the same point. We know the landing site but as Vikram deviated from the path at the last minute during the final descent, we have to look in an area of 10 x 10 km area from three payloads SAR, IR spectrometer and camera. We have to do high-resolution imaging of the area to find Vikram."
Last edited by Ashokk on 07 Sep 2019 23:12, edited 1 time in total.

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Re: Chandrayan-2 Mission

Postby SSSalvi » 07 Sep 2019 23:09

A good scientific analysis showing that the communication failed at 20:20:01 UT.

Those people use telemetry from official telemetry partner.


[url]. https://mobile.twitter.com/cgbassa/stat ... 7775109120[/url]

Please avoid discussions on comments from others.. let's concentrate on scientific content.

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Re: Chandrayan-2 Mission

Postby Arjun » 07 Sep 2019 23:17

That's 1:50am IST

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Re: Chandrayan-2 Mission

Postby disha » 07 Sep 2019 23:20

chetak wrote:
If true, about shifting to two retro rockets during the last stages

four retro rockets would have been a better way to go, especially in the final stages.

the general principle being a risk is reduced as the criticality increases


I thought it was shifting to a single central rocket engine in the final phase. The reason to shift was to not kick up sharp moon dust and damage the lander.

From the chatter, it appears that issue was even before the cutover to single (or two) engines.

At this stage, without a formal RCA from ISRO it appears that:

1. One of the retro rockets underperformed causing the other three to overcompensate and send the lander into an irrecoverable spin.

Now:

1. What caused underperformance in retro rocket? A hardware glitch? A software error?

2. Overcompensating retro rockets sending the lander into a spin (or spin and tumble) is definitely due to a software error. Again this is a very complex algorithm and it might have just run into an area beyond its designed limit.

Quoting from Scientific Advisor:

The Vikram Lander followed the planned descent trajectory from its orbit of 35 km to just below 2 km above the surface.

All systems and sensors of the Lander functioned excellently until this point. Tested and proved many new technologies such as the variable thrust propulsion technology used in the Lander.


Variable thrust propulsion technology is very complex. Think of it as a perfect synchronization between analog and digital domains at millisecond response times.

Getting to that was never easy. It appears that we have some glitches to solve but we are almost there.
Last edited by disha on 07 Sep 2019 23:46, edited 1 time in total.

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Re: Chandrayan-2 Mission

Postby madhu » 07 Sep 2019 23:27

PrannoyRoyNDTV
I agree. It’s absolutely sick. Yes, Pallava made a mistake, a terrible rude mistake and NDTV has said so. Pallava has apologised - sincerely. He has apologised to NDTV too. That’s it. Pallava has done more for ISRO & India’s science than all the ghastly trolls put together.

https://twitter.com/PrannoyRoyNDTV/stat ... 69729?s=19

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Re: Chandrayan-2 Mission

Postby Gagan » 07 Sep 2019 23:41

No
Pallav Bagla needs to pay for his arrogance
He should be shadow banned by ISRO and GoI for an extended period

Even when he was "doing so much for Indian science" he was slyly asking single digit IQ marxist type questions, like how do you justify a space program when India is so poor, and asking the DAE chief if the S1 reactor was designed and built in India.

These mediawalas are freeloading smart-arses. They hoity-toitily arrive with a camera and a mike and put our scientists and military officers under a third degree type interrogation, and being sarcastic all the time. They have no business behaving in such a manner.
Need to be made an example of !!!

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Re: Chandrayan-2 Mission

Postby sudarshan » 07 Sep 2019 23:49

Well then now is the chance, right? The "Ghastly Trolls" should now dig up old footage of the Bagla's antics and put it up for all to see how much he has "done for ISRO."

That Doppler curve shows steady deceleration during the rough braking phase. If the craft were tumbling then, the deceleration would have been erratic (since the direction of rocket acceleration would be unsteady), and would have showed in the Doppler plot. Then the rough braking ends, and unfortunately, the comms fail within a second of that point. For that one second, though, the plot seems steady. So no change in velocity of craft for that one second from 2:19 to 2:20?

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Re: Chandrayan-2 Mission

Postby Gagan » 07 Sep 2019 23:59

Guys is this confirmed?

https://twitter.com/vasudevan49/status/ ... 3610146816
Vasudevan Iyengar wrote:Latest update:
Lander found 500m away from the actual landing spot. But almost upside down. Seen from OHRC image and it is intact!
Trying to send commands from Bangalore control center...

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Re: Chandrayan-2 Mission

Postby disha » 08 Sep 2019 00:01

madhu wrote:PrannoyRoyNDTV
I agree. It’s absolutely sick. Yes, Pallava made a mistake, a terrible rude mistake and NDTV has said so. Pallava has apologised - sincerely. He has apologised to NDTV too. That’s it. Pallava has done more for ISRO & India’s science than all the ghastly trolls put together.

https://twitter.com/PrannoyRoyNDTV/stat ... 69729?s=19


rNDTV needs to be boycotted. Above is not an apology. Above statement from arrogant_Prannoy is more an entitlement. That his outburst was not misplaced because Ballav Pagla has "more for ISRO & India's science than all the ghastly trolls put together". And calling out Ballav Pagla's screeching entitled outburst puts us into ghastly trolls category.

Both arrogant_Prannoy and stupid_Nidhi came out in support of Ballav Pagla. In fact stupid_Nidhi said that ISRO's chief is answerable to a Journo. ISRO's chief is answerable only to his boss, the PM of India.

PS: Madhu'ji please do not post any more drivel from rNDTV in this thread. Or on this forum. Of course you can post all the glorious contributions of Ballav Pagla to ISRO and India's science.

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Re: Chandrayan-2 Mission

Postby chetak » 08 Sep 2019 00:04

Gagan wrote:No
Pallav Bagla needs to pay for his arrogance
He should be shadow banned by ISRO and GoI for an extended period

Even when he was "doing so much for Indian science" he was slyly asking single digit IQ marxist type questions, like how do you justify a space program when India is so poor, and asking the DAE chief if the S1 reactor was designed and built in India.

These mediawalas are freeloading smart-arses. They hoity-toitily arrive with a camera and a mike and put our scientists and military officers under a third degree type interrogation, and being sarcastic all the time. They have no business behaving in such a manner.
Need to be made an example of !!!



bagla seems to be some sort of patti wallah, meaning well connected and influential.

his lack of IQ is apparent and his arrogant demeanor for many many years now is proof of the fact that family connections beat competence in lala outfits like runditv.

simply withdraw his govt access pass and let him do the pani puri beat, reporting from the grimy dhabas of old dilli and go running back home every evening with an upset dilli belly.

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Re: Chandrayan-2 Mission

Postby UlanBatori » 08 Sep 2019 00:06

Remember to do the essential. Banning the Pagal is EZ. But this is a chance to get NDTV's boss kicked out. Poll the advertisers on NDTV.

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Re: Chandrayan-2 Mission

Postby disha » 08 Sep 2019 00:08

sudarshan wrote:That Doppler curve shows steady deceleration during the rough braking phase. If the craft were tumbling then, the deceleration would have been erratic (since the direction of rocket acceleration would be unsteady), and would have showed in the Doppler plot. Then the rough braking ends, and unfortunately, the comms fail within a second of that point. ...


Sudharshan'ji craft was definitely *not* tumbling during the rough descent phase. That went flawless.

I think the cutover from rough descent to smooth landing was not even. What could be the reasons?

We need to break down into sequences the smooth landing phase and maybe given public information try to localize the issues.

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Re: Chandrayan-2 Mission

Postby SriKumar » 08 Sep 2019 00:10

madhu wrote:PrannoyRoyNDTV
I agree. It’s absolutely sick. Yes, Pallava made a mistake, a terrible rude mistake and NDTV has said so. Pallava has apologised - sincerely. He has apologised to NDTV too. That’s it. Pallava has done more for ISRO & India’s science than all the ghastly trolls put together.

https://twitter.com/PrannoyRoyNDTV/stat ... 69729?s=19

This is Prannoy Roy covering for Pallav Bagla. Guys remember, it is not PB disrespecting just Sivan. He is disrespecting the Office of the Chairman, and also publicly (!) insulted the stand-in ISRO scientist answering questions by calling him a 'junior'- whatever that means. The office is more important than the person (just like the Prime Minister's office is bigger than Narendra Modi or MMS).

PB is used to doing this kind of sh*t, and such uncultured, self-important, entitled, arrogant, bumpkins have no place in a room where people are discoursing on serious science and engineering (i.e. the ISRO presser). Other reporters were more balanced.

Pallav Bagla is critical neither to science nor to press freedom, and is highly replaceable in both respects. NDTV can pay his salary- no quibble from my side, it is Prannoy's money to waste. But PB should be persona non grata on ISRO pressers. And this is to protect the dignity of office, and not K. Sivan or the other ISRO scientist who received his hectoring. ISRO should take organizational cognizance of this exchange and not treat it like a public insult to the chairperson (which is bad enough). UB's suggestion of extending this generosity to the CEO is apt as well.

My last on this OT.
Last edited by SriKumar on 08 Sep 2019 00:12, edited 1 time in total.

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Re: Chandrayan-2 Mission

Postby UlanBatori » 08 Sep 2019 00:11

Great that the lander is found! Chances of raising on comm is very slim: probably solar panels did not deploy, no real power source except for any backup batteries.

You know the **ONLY** ones who can reach there -- because they are already crawling there, right? They COULD be persuaded to take a repair kit there, in a truly spectacular demo of international bhai-behen and technology. Robotic/ Telepresence repair and recovery.

If it didn't crater in, the thrusters wer not pointed upwards, so then it may have had a lot of thrust acting to slow it down, the poor Autopilot may have tried its best and started recovering... so impact may have been quite slow. And survivable for the Rover. But the mechanisms to get it out may be kaput. Worth a shot, I would say: call Beijing. No dishonor in participating a mind-boggling extraterrestrial rescue/repair.

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Re: Chandrayan-2 Mission

Postby Mort Walker » 08 Sep 2019 00:12

Gagan wrote:Guys is this confirmed?

https://twitter.com/vasudevan49/status/ ... 3610146816
Vasudevan Iyengar wrote:Latest update:
Lander found 500m away from the actual landing spot. But almost upside down. Seen from OHRC image and it is intact!
Trying to send commands from Bangalore control center...


Any other unofficial confirmation on this or this just another twitter rumor?

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Re: Chandrayan-2 Mission

Postby Picklu » 08 Sep 2019 00:15

Gagan wrote:No
Pallav Bagla needs to pay for his arrogance
He should be shadow banned by ISRO and GoI for an extended period

Even when he was "doing so much for Indian science" he was slyly asking single digit IQ marxist type questions, like how do you justify a space program when India is so poor, and asking the DAE chief if the S1 reactor was designed and built in India.

These mediawalas are freeloading smart-arses. They hoity-toitily arrive with a camera and a mike and put our scientists and military officers under a third degree type interrogation, and being sarcastic all the time. They have no business behaving in such a manner.
Need to be made an example of !!!


I do not differ on the arrogance part. My personal opinion is a sincere public apology should be good enough for first offence; repeat offenders can be censored/punished more harshly.

However, it is indeed true that Pallava is covering space and science in positive manner in india for a long duration(more than past one decade when it was not fashionable) and some slack should be cut for past services.

Note:

1. There were dumb questions, true. But we need to keep in mind that the goal was to reach the larger audience and not only to restrict it to knowledgeable BRF like crowd and that larger audience would have some really basic questions so the popular science kind of writer/interviewer would cover them knowingly. I still remember Prof. Yash Pal explaining patiently why all the water on the planet earth do not fall away from the "bottom" (i.e. south pole) of it in "Turning Point" on Doordarshan but then I am an old codger compared to the "Payel Rohtagi" class of millennial RW foot soldiers.

2. More and more, I find the RW digital/social media presence is taking the form of "the saffroner shade win" similar to "the greener shade win" of paki version (albeit our is on digital format whereas pakis usually start with ak47 and hold the the pin of of the suicide vest as backup). We are essentially using people in a "use and throw" mode with no consideration of their past contribution. Vishnu Som, Shiv Aroor - all get our goat at the first disagreement with majority view. Pallava is getting it now. Sourbh Jha, YousufDFI, TS Subramanian and Y Mallikarjun are all just one disagreement away to be branded traitor. This is not a good trait; we should not be lamenting later why "Rajputs/Marathas/Shikh/your favourite..." could not unite together against "mughal/british/your choice of invader" while being harsh/unforgiving for genuine mistakes. At no point I am suggesting that Ajay Sukla, Praveen Swamy, Rajat Pandit, Rahul Bedi, Saikat Dutta and such should be given any leeway, they are poisonous snake and should be treated such. But we need to separate them from the others and treat the others slightly differently. Often there is virtually no difference between the treatment of the two class and if the other class start loosing hope ultimately the indic system would be looser.

3. More and more it appears to chance to hit rNDTV via Pallava. I do not differ on the nature of rNDTV; then should be put to sleep. My points are strictly limited to the persons involved. 99% of rNDTV are blue blood traitors.
Last edited by Picklu on 08 Sep 2019 00:22, edited 2 times in total.


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